Crowdsourced smartphone data reveal altered sleep/wake pattern in quarantined Chinese during the COVID-19 outbreak.

The Chinese Government quarantined Wuhan on 23 January 2020 and thereafter the Hubei province, affecting a total of 59 million citizens, to cease the spread of the coronavirus disease in 2019 (COVID-19). The effects of this lockdown on the psychological and mental health of both the affected and unaffected Chinese are largely unknown currently. We utilized one of the largest crowdsourced databases (Sleep as Android) that consisted of 15,681 sleep records from 563 users in China to estimate the change in the sleep pattern of Chinese users during the span of 30 December 2019 to 8 March 2020 with reference to 64,378 sleep records of 1,628 users for the same calendar period of years 2011-2019. The sleep pattern in China changed drastically after 23 January 2020 when the law of quarantine and suspension of Wuhan became effective. The two major findings are: (1) Chinese people increased their sleep duration by an average of 20 min and delayed their sleep onset by an average of 30 min at weekdays, while they maintained a similar sleep duration at weekends, and (2) larger changes were found in several subgroups, including those in Wuhan (80 sleep records from 3 users), female subjects, and those aged ≤ 24 years. Overall, Chinese people slept later and longer than usual during the COVID-19 pandemic quarantine.